1. Field of the Invention
The present invention relates to enhancing the surface of a material for cleaning, material removal for the preparation of adhesive bonding or etching, and more particularly, to the generation and use of neutral, chemically active particles to chemically react with a material surface, so as to alter the surface as desired for the cleaning, material removal or preparation for adhesive bonding or etching.
2. Description of the Related Art
Large scale low-temperature plasma related methods and devices are needed for surface cleaning and pre-conditioning materials, for both laboratory, manufacturing, and field applications. One of the problems encountered in developing such procedures and devices is scaling up specific processing environments, which produces desired material effects on a small scale, such that large scale exposure can be effectively performed. The coupling of system parameters is strong for low-temperature plasma systems. This coupling makes scaleup difficult since both substrate temperatures and reactive species need to be controlled or altered, and since the coupling of operating parameters which influence reactivity and temperatures severely restrict the degree of such controllability. There are no process models or experimental database, or other knowledge database which permit scaleup system design.
Systems are needed for plasma processing a broad scope of materials for field and manufacturing applications. Critical to cost effectiveness is flexibility in design for the purpose of varying plasma generated environments over materials to be processed.
U.S. Pat. No. 4,588,641, issued to Haque et al., discloses a 3-step plasma treatment for improving a laminate adhesion of metallic and non-metallic substrates. The treatment comprises sequentially exposing the substrate to a first plasma of oxygen gas, a second plasma of a hydrocarbon monomer gas and a third plasma of oxygen gas. The process has particular utility in forming polymeric films on one or more surfaces of copper or copper alloy foils to be used in printed circuit applications.
U.S. Pat. No. 3,462,335, issued to R. H. Hansen et al., discloses subjecting hydrocarbon, fluorocarbon and polyamide polymers to a stream of excited inert gas.
U.S. Pat. No. 4,765,860, issued to S. Ueno et al., discloses a method for the preparation of a flexible base for printed circuit board of the type formed of lamination of a flexible sheet-like polymeric base and a metal, e.g. copper, foil adhesively bonded thereof by use of an adhesive, in which the surface of the polymeric base prior to bonding of the metal foil is subjected to exposure to low temperature plasma so that the adhesive bonding strength between the polymeric base and the metal foil can be improved.
None of the above described references discusses plasma processing systems for cost effective and flexible design field and manufacturing applications which vary plasma generated environments over a variety of materials to be processed.